gardening, indoors & out

House plants

…to bring the last of your houseplants indoors if they have been holidaying outside.

Here in the far south east of England the temperatures have dropped to about 3c overnight, which means that even the mediterranean-type plants (those hardy to just above or brief periods below 0c) will need protection.

If you are faced with squeezing the last of your plants into an overcrowded living environment you are not alone, this is what I have learned from years of trying.

Coming in from the cold

You will need to tidy up your plants before you bring them in – remove weed seedlings, dead`and damaged leaves and check under the pot. This is where the slugs and snails hide. If you have bare compost you can top with grit or gravel, this makes the plant easier to water and also discourages sciarid flies (often known as bin flies or compost gnats) that live around compost. Check to see how damp the compost is, so that you are able to bring them into synchrony with your watering routine. If it has rained recently and they are soaked through, you may not need to water for a couple of weeks, but this is very dependant on where you site them (sun/shade) and how warm your home is.

During the summer your plants will have become accustomed to a lot more light than they will receive in your home (unless they are to move into a conservatory or similar). They will also have grown a bit tougher and stronger through dealing with wind and rain. They will need good daylight, and also a period of adjustment to the change in conditions. Depending on the number of plants you have, you may need to prioritise the light levels; south and west facing windowsills for cacti and succulents, north facing for dark-leaved foliage plants etc. You will also need to find them saucers or pot-covers so that they don’t drip onto your surfaces.

Containers and pot-covers

In my experience the use of pot-covers and containers is the main reason that people overwater their plants. The plant can sit for weeks or months in a puddle of water without it being obvious until it is too late. If you know that you are an nurturer and overwater your plants, use attractive pots with drainage and either matching saucers or transparent plastic ones. Alternatively you can use a layer of 1cm or so of gravel at the bottom of your pot to give yourself a safety margin. Or get into the routine of emptying out your pot-covers an hour after each watering.

Space creation

I never have enough space as I have a tendency to buy plants over the summer when I have a comparatively empty indoor space, and then quail in horror each autumn when I realise I have to house all of them. This is what I do to get past this problem.

You can expand your windowsill space using shelving (or if you are in a rental, a piece of driftwood balanced on pots). This enables you to make use of as much light as possible and gives you an attractive display.You will note that i am using a range of saucers and containers, partly because I err towards the neglectful, so I can get away with some undrained containers. There is a terracotta saucer being used in addition to the plastic tray for one pot, this because unglazed terracotta is porous and will damage surfaces that it sits upon; it will (as a friend can testify) turn carpet mouldy underneath and raise paint and varnish.

Put plants on top of other plants – if you have larger plants like this Ficus lyrata you will have a whole extra surface to keep things on. When you are doing it, bear in mind how much light will make it down to the understorey of your houseplant forest. As you can see by the graininess of this photo, it isn’t very light here, but Aspidistra ‘Milky Way’ is quite tolerant of low light levels.

Another example here, a Philodendron bipinnatifidum (in a cat bed that the cat disapproves of) supporting a Tradescantia and a Ledebouria. The philodendron spent the whole summer outside, and is stretching (etiolating) in the comparatively low light indoors, the leaves stay the same size but the stalks extend to get closer to the light.

You can also use mirrors (one here propped up on the floor with a spider plant) to reflect the light you have to make the most of it. If like me, you also have a lot of air plants, they are very happy pinned to chicken wire screens (mine is hung from the curtain hooks) over a window. And at the bottom, many of my cacti and succulents together, taking advantage of their similar cultural requirements to make my life easier.

Supplementary lighting

I have not found supplementary lighting much use in a domestic environment for houseplants. The majority of lighting that is suitable for plants (in terms of wavelength, strength and heat transmission) has to be placed very close to them to be of any benefit, and therefore tends not to be either practical or aesthetically pleasing. However, with LEDs becoming much more common in these field I am hoping that eventually gains in this area will carry over from commercial and er.. underground horticulture to create something usable in the average home.

Remember to give your plants time to adjust, and keep an eye out for sneaky pests like tortrix moth caterpillar (see above on begonia), and sudden changes in growth habit (can be a sign of overwatering).

This year I developed a ‘thing’ about air plants. It started with buying just one, meaning to attach it to an object to make a present for someone. Almost in the same way that you would stick on a sequin I guess. But of course, as soon as I actually touched it, I remembered that it was a life-form, not a bit of plastic.

So I got a couple more, and started trying to understand how they work. The easiest to observe in a short period of time (air plants live in slow time) is Tillandsia caput-medusae.

Tillandsia, named for Mr Tillandz (1640-1693) a Finnish botanist, by Linnaeus (many thanks Wikipedia) is a big genus, part of the Bromeliaceae family. They tend to originate in South and Central America, though not exclusively. Tillandsia caput-medusae invites comparison between the structure of the plant and the snake-hair of the Medusa’s head (lit. caput medusae). There are 4 specimens above, and you can see how they do (or don’t) fit the picture below. They tend to coil slightly more tightly when they are in need of watering.

Tillandsias are popularly known as air plants, which probably leads to the death of thousands in the home. The ‘air’ in air plant refers to their epiphytic nature: they live in air (on other plants, rocks, trees, phone wires, etc) rather than in soil. They don’t live on air, particularly not in centrally-heated domestic homes.

In the absence of roots, tillandsias absorb both water and nutrients through silvery trichomes on the surface of their leaves – seen in the above photo. These trichomes have three functions for the plant: their silvery colour reflects bright sunlight, they allow water to be absorbed from rain and atmospheric humidity, and they protect that water from evaporating once it has been captured. If you have an airplant, it is important that you bear this in mind when you are caring for it. It needs access to water regularly or it will die of dehydration, but it is in danger of rotting if the water is allowed to gather and rest in the spaces between the leaves.

Watering should therefore be done once or twice a week, depending on the conditions the plant is living it (sunny window in warm conditions – twice; no sun, chillier conditions – once). All it needs is to be run under the tap, or popped in a bowl of water for a bit. If your plant gets dehydrated leave it in a bowl of water overnight. As with all houseplants, it really helps to understand how your plant feels when it is healthy. You won’t damage it if you handle it regularly, as long as you are careful. A healthy plant will feel slightly cooler than ambient, and it will feel gently springy rather than crispy in your hand. This will vary between species of tillandsia, but for caput-medusae firm and gently springy is good.

Then drain it (on a teatowel or whatever comes to hand) for an hour or two, upside down so that the water can drain out from between the leaves. If your plant is growing upside down anyway, so much the better.

One of my caput-medusae caught me out by flowering long before I had expected it to. I am told that one way to encourage them to flower is to feed (weekly-weakly) with very dilute plant food, I use about 1/10th the recommended rate for my plants. As you can see on the photo above the flower-stem comes from the centre of the plant in this case, and starts off green with pink tinges.

The inflorescence takes quite a while to develop, but once the purple flowers appear they last a very short time, slightly less than a day per flower with this plant. That said, the flowers are produced one at a time, so the display is quite long-lasting, and immensely attractive.

And once the flowers fade, the plant should move on to producing an offset (a clone plant that remains attached to the parent until it is of sufficient size to live independently). You can just see the offset nestling in an older leaf at the bottom of the plant here.

Over time, the plants will produce a mass of many plants. Pictures of plants in the wild here, and here.

Update photos of offset: 8-10-16. (The wire is not for the purpose of restraint but suspension).

This is my oldest houseplant – jokingly named Austin (as in Austin Morris a long-defunct British car manufacturer) – a Monstera deliciosa purchased in Leicester Marks & Spencer in 1987, when I was in the last year of a degree in English and Politics.

I had owned houseplants before, but I was not possessed of green fingers and they all died horribly, much to the dismay of my mother. But this one survived and grew; it moved back home with me on the train when I left. The Monstera became the first of many plants, and the first of many moves with all of them. I have taken cuttings and given them away, and several times cut down and repotted the original plant so as to ensure it remains a feasible size and shape to fit in a small home. By my estimates I have moved house about 20 times, and each time taken this plant with me. The last move required help as it has grown too large for me to move easily by myself -see photo!

When I bought the Monstera I had no real interest in plants, I was just a bit lonely in a house full of medical students from another university and wanted another living thing to keep me company. But something about the cool of the leaves, and the vibrancy of their life attracted me. Over time I acquired many more houseplants; it was a long time before I had any outdoor space so the thought of garden plants didn’t arise. I read as much as I could about their origin and care, and filled my desk in an insurance company with plants.

In my late twenties, stuck for a life plan and bored with my job I decided to take a correspondence course in horticulture. None of the courses ever mentioned indoor plants, but I figured that plants were plants, so it wouldn’t really matter. By the time I was in my early 30s I had changed jobs and was working (oddly enough, sometimes in the houseplant area) in a garden centre. A very large proportion of my income went directly into the till, as working with plants creates an almost inexhaustible hunger for new ones. Having now worked in horticulture in several different roles for nearly twenty years, I often look at Austin and wonder what would have happened if I hadn’t needed some company in 1987.

My very small flat is currently home to about 60 houseplants, and I will tell some of the stories that attach to each plant. If you have a houseplant story, or have lived a life full of houseplants, let me know.